“Look at those skull images over there.” Hak was speaking to Ponter through a pair of cochlear implants, but by changing the left-right balance of his voice he could indicate a direction as surely as if he had pointed. Ponter got up—shakily—and crossed the room, heading away from the strange beings and approaching an illuminated panel like the one they were looking at, with several deepviews of skulls clipped to it.

“Green meat!” said Ponter, looking at the strange skulls. “They are Gliksins—aren’t they?”

“I would say so. No other primate has that lack of browridge, or that projection from the front of the lower jaw.”

“Gliksins! But they’ve been extinct for—well, for how long?”

“Perhaps 400,000 months,” said Hak.

“But this can’t possibly be Earth of that long ago,” said Ponter. “I mean, there’s no way the civilization we’ve seen would have failed to leave traces in the archeological record. At best, Gliksins chipped stone into crude choppers, right?”

“Yes.”

Ponter tried to keep from sounding hysterical. “So, again, where are we?”

Reuben Montego looked agape at the casualty officer, Dr. Singh. “What do you mean, ‘He appears to be a Neanderthal’?”

“The skull features are absolutely diagnostic,” said Singh. “Believe me: I’ve got a degree in craniology.”

“But how can that be, Dr. Singh? Neanderthals have been extinct for millions of years.”

“Actually, only for 27,000 years or so,” said Singh, “if you accept the validity of some recent finds. If those finds prove spurious, then they died out 35,000 years ago.”

“But then how …”

“That I do not know.” Singh waved his hand at the x-rays clipped to the illuminated panel. “But the suite of characters visible here is unmistakable. One or two might happen in any given modern Homo sapiens skull. But all of them? Never.”

“What characters?” asked Reuben.

“The browridge, obviously,” said Singh. “Note that it is unlike other primate browridges: it is doubly arched, and has a sulcus behind it. The way the face is drawn forward. The prognathism—just look at that jaw jut out! The lack of a chin. The retromolar gap”—he pointed to the space behind the last tooth. “And see those triangular projections into the nasal cavity? Those are found in no other mammal, let alone any other primate.” He tapped the image of the skull’s rear. “And see this rounded projection at the back? That is called the occipital bun; again, it’s distinctly Neanderthaloid.”

“You’re pulling my leg,” said Reuben.

“This is something I would never do.”

Reuben looked back at the stranger, who had gotten up out of the wheelchair and was now staring, with astonishment, at a couple of skull x-rays on the other side of the room. Reuben then looked again at the x-ray film in front of him. Both he and Singh had been out of the room when the technician had taken the pictures; it was possible that, for whatever reason, someone had substituted different shots, although—

Although these were real x-rays, and they were x-rays of a living head, not a fossil: nasal cartilage and the outline of flesh were clearly visible. Still, there was something very strange about the lower jaw. Parts of it showed as a much lighter shade of gray in the x-ray, as if they were made of a less-dense material. And those parts were smooth, featureless, as though the material was uniform in composition.

“It’s a fake,” said Reuben, pointing to the anomalous part of the jaw. “I mean—he’s a fake; he’s had plastic surgery to make himself look Neanderthal.”

Singh squinted at the x-ray. “There is reconstructive work here, yes—but only in the mandible. The cranial features all seem to be natural.”

Reuben glanced at the injured man, who was still looking at other skull x-rays while babbling to himself. The doctor tried to imagine the stranger’s skull beneath his skin. Would it have looked like the one Singh was now showing him?

“He has several artificial teeth,” said Singh, still studying the x-ray. “But they’re all attached to the section of jaw that has been reconstructed. As for the rest of the teeth, they seem natural, although the roots are taurodontid—another Neanderthaloid trait.”

Reuben turned back to the x-ray. “No cavities,” he said, absently.

“That is right,” said Singh. He took a moment to assess the x-rays. “In any event, he seems to have no subdural hematoma, nor any skull fracture. There is no reason to keep him in hospital.”

Reuben looked at the stranger. Who the hell could he be? He babbled in some strange tongue, and he’d had extensive reconstructive surgery. Could he be a member of some bizarre cult? Was that why he’d broken into the neutrino observatory? It made a certain amount of sense, but—

But Singh was right; except for the mandibular restoration, what they were seeing in the x-ray was a natural skull. Reuben Montego crossed the room slowly, warily, as if—Reuben realized within a few moments what he was doing: he was approaching the stranger not as one would approach another human being, but rather as one might come near a wild animal. And yet there had been nothing in his manner so far to suggest anything except civility.

The man clearly heard Reuben approaching. He took his attention away from the x-rays he’d been captivated by and turned to face the doctor.

Reuben stared at the man. He had noted earlier that his face was strange. The browridge, arching above each eye, was obvious. His hair was parted precisely in the middle, not at either side, and it looked like that was the natural part, not some affectation. And the nose: the nose was huge—but it wasn’t the least bit aquiline. In fact, it wasn’t quite like any other nose Reuben had ever seen before; it completely lacked a bridge.

Reuben lifted his right hand slowly, fingers gently spread, making sure the gesture looked tentative, not threatening. “May I?” he said, moving his hand closer to the stranger’s face.

The man might not have understood the words, but the intent of the gesture was obvious. He tilted his head forward, inviting the touch. Reuben ran his fingers along the browridge, over his forehead, along the length of the skull from front to back, feeling the—what had Singh called it?—the occipital bun at the rear, a hard dome of bone beneath the skin. There was no doubt at all: the skull shown in the x-rays belonged to this person.

“Reuben,” said Dr. Montego, touching his own chest. “Roo-ben.” He then gestured at the stranger with an upturned palm.

“Ponter,” said the stranger, in a deep, sonorous voice.

Of course, the stranger might be taking “Reuben” to be the term for Montego’s kind of humanity, and “Ponter” might be the stranger’s word for Neanderthal.

Singh moved over to join them. “Naonihal,” he said—revealing what the N stood for on his nametag. “My name is Naonihal.”

“Ponter,” repeated the stranger. Other interpretations were still possible, thought Reuben, but it did seem likely that was the man’s name.

Reuben nodded at the Sikh. “Thank you for your help.” He then turned to Ponter and motioned for him to follow. “Come on.”

The man moved toward the wheelchair.

“No,” said Reuben. “No, you’re fine.”

He gestured again for him to follow, and the man did so, on foot. Singh undipped the x-rays, put them in a large envelope, and walked out with them, heading back to Emergency Admitting.

Frosted glass doors blocked the way ahead. As Singh stepped on the rubber mat in front of the doors, they slid aside, and—

Electronic flashes exploded in their faces.

“Is this the guy who blew up SNO?” called a male voice.

“What charges are Inco going to lay?” asked a female one.

“Is he injured?” called another male.